NAICS 335311: Power
This U.S. industry comprises establishments primarily engaged in manufacturing power, distribution, and specialty transformers (except electronic components).  Industrial-type and consumer-type transformers in this industry vary (e.g., step up or step down) voltage but do not convert alternating to direct or direct to alternating current.

Illustrative Examples:

Fluorescent ballasts (i.e., transformers) manufacturing
Substation transformers, electric power distribution, manufacturing
Distribution transformers, electric, manufacturing
Transmission and distribution voltage regulators manufacturing

ExioML sector: Electrical machinery and apparatus n.e.c. (31)
Region: US | Year: 2022
Sector value added: 68675.5386579 M EUR | Employment: 809.436143123 thousand persons
Sector GHG emissions: 3051654294.78 kg CO2 eq | Energy carrier net total: 101481.364669 TJ | Carbon intensity: 0.04443582612408031

Company: Prolec-GE Waukesha Inc
Recognized as one of the largest U.S. manufacturers of power transformers from 5 to 1200 MVA, up to 345kV, the company designs, builds and tests its transformers according to IEEE, ANSI, NEMA and ISO 9001:2015 technical and quality standards.